Lead-free bismuth pyrochlore-based dielectric films for ultrahigh energy storage capacitors

We developed ultra-high energy storage density capacitors using a new class of lead-free bismuth pyrochlore-based dielectric film material systems with high breakdown strength and reliability. The 2 μm-thick pyrochlore ceramic film capacitors have demonstrated ultra-high energy densities around 90 J/cm³ with very low energy loss below 3%, which is achieved by the combination of high permittivity, pseudo-linear dielectric characteristics, and high breakdown electric field over 4.5 MV/cm. Particularly, these pyrochlore ceramic films can endure voltage strength up to ∼900 V. These noteworthy pyrochlore ceramic films are fabricated by the low-cost chemical solution deposition process which allows dielectric films to be processed on standard platinized silicon wafers. This new class of capacitors can satisfy the emergent needs for significant reduction in size and weight of capacitors with high energy storage capability in power electronics, electric vehicles, and energy storage in sustainable energy systems. Our research provides a unique and economical platform for the processing of this useful pyrochlore material in large volume for eco-friendly energy applications.